Birthday Calendar by Karel Martens

Karel Martens is a Dutch graphic designer and typographer known for playful, geometric work built from simple printing techniques — punches, overlaps, layered colour. This wall calendar started as a prototype he made in 1968 and sat unproduced for decades before finally being released.

The layered, multi-hued pattern is based on a single geometric shape, punched out of coloured cardstock and rotated in multiple directions across the page. 14 pages, in English, sized 30 × 42 cm for hanging on a wall.